- 9 -
RAID row
(RAID cell in
one row)
1. One 4-disk RAID 0 volume: RAID width= 4; RAID
copy=1; RAID row=1.
2. One 3-way mirroring volume: RAID width=1; RAID
copy=3; RAID row=1.
3. One RAID 10 volume over 3 4-disk RAID 1 volume:
RAID width=1; RAID copy=4; RAID row=3.
WT
W
rite-
T
hrough cache-write policy. A caching technique in
which the completion of a write request is not signaled until
data is safely stored in non-volatile media. Each data is
synchronized in both data cache and accessed physical
disks.
WB
W
rite-
B
ack cache-write policy. A caching technique in which
the completion of a write request is signaled as soon as the
data is in cache and actual writing to non-volatile media
occurs at a later time. It speeds up system write performance
but needs to bear the risk where data may be inconsistent
between data cache and the physical disks in one short time
interval.
RO
Set the volume to be
R
ead-
O
nly.
DS
D
edicated
S
pare disks. The spare disks are only used by one
specific VG. Others could not use these dedicated spare
disks for any rebuilding purpose.
GS
G
lobal
S
pare disks. GS is shared for rebuilding purpose. If
some VGs need to use the global spare disks for rebuilding,
they could get the spare disks out from the common spare
disks pool for such requirement.
DC
D
edicated
C
ache.
GC
G
lobal
C
ache.
DG
D
e
G
raded mode. Not all of the array’s member disks are
functioning, but the array is able to respond to application
